Structural control of a cobalt nanocone array grown by directional electrodeposition

A metallic nanocone array by means of a directional electrodeposition method without any template is reported. With the crystallization modifier in the nickel electroplating solution, the cobalt conical structure can be deposited onto different metal substrates. The morphology of the nanocones can be controlled by changing the electroplating condition. The as-prepared Co nanocones grow preferentially along <110> directions with very sharp tips. The conical structures are single crystalline without any disruption of the lattice planes. The growth mechanism is also briefly discussed.